Hunters, golfers, and other outdoor enthusiasts frequently desire to determine real-time wind direction, even when the magnitude of the wind is so slight that the outdoor enthusiast can not directly sense the wind on his or her person. For example, a failure to know even the slightest wind direction has been a constant challenge for hunters of large game, because the hunter may find himself or herself upwind from the hunted animal, thereby alerting the hunted animal to the hunter's presence. Further, hunters of waterfowl generally desire to set their decoys or hunt downwind of the waterfowl, even if the wind is imperceptible by the hunter, because birds generally land into the wind. Moreover, real-time knowledge of the wind direction is useful to golfers in selecting the correct golf club and aligning their stance to achieve the desired targeting on a shot. Knowledge of wind direction is also desirable in other recreational sports such as hiking, archery, badminton, and other outdoor activities that are affected by the wind direction. Detecting wind direction or the flow of other fluids has non-recreational applications as well, including emergency management of chemical spills, fire fighting, etc.
Various devices, systems, and methods exist for detecting wind direction. Such devices range in complexity from simple mechanical weather vanes to complex weather stations that precisely measure both wind direction and speed. However, the usefulness of these devices to an outdoor enthusiast is often limited by their size, weight, cost, lack of portability, and ability to detect wind with a very small magnitude. These devices may also be limited in use under low light conditions.
Many simple methods for measuring wind direction also exist in the art. For example, an outdoor enthusiast may throw a handful of grass, dirt, or other lightweight material in to the air and watch the direction the material moves to determine wind direction. However, in the case of a hunter, the sudden movement of the hunter as well as the sudden appearance of a cloud of dark material could be detected by the hunted animal. Chemical smoke or powder dispensers are also known in the art to provide an indication of wind direction. However, under some circumstances, particularly if the hunter is already positioned partially upwind from the hunted animal, the chemical odor may be detected by the animal. Further, such methods are not particularly effective in low light situations, where the outdoor enthusiast cannot adequately see the grass, dirt, or chemical.
Other methods, such as wetting the outdoor enthusiast's finger and monitoring which side of the finger cools and/or dries first, may not offer adequate information when the magnitude of the wind is slight or the temperature is too cold to feel cooling and/or drying on a particular side of the outdoor enthusiast's finger. Similarly, a piece of hanging string or thread may be too heavy to move in the direction of a slight wind. Moreover, the piece of hanging string or thread may also be difficult to see in low light conditions.